Automatic safety-latch for furnace-doors



E. L. BURKY. AUTOMATIC SAFETY LATCH FOR FURNACE DOORS.

APPLICATION FILED MAY l2. 1920. 1,371,547.

Patented Mar. 15, 1921,

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EDWARD n. BURKY, or Drtnxnr. 1111.1., PENNsYLvANrA, Assistme; F ONEHALF T@ FRED C. SPAULDING, OF .ARDMOREL PEN'NSYLJJANlili.a

AUTOMATIC SAFETY-LATCH FOR FURNACE-DOORES.

Specification of Letters Patent. Paignted Mar, t5, 192i Application filed May 12, 1920. Serial No. 380,774.

and furnace fronts, its objectbeing the production of a simple, inexpensive, efficient and automatically operated latch which will insure the automatic latching of a furnace door during the closing thereof so as to prevent the possibility of its being blown 21o out, the unlocking of the device being effected simultaneously withthe opening of the door, as will be hereinafter described.

For the purpose of illustrating my invention, l have shown in the accompanying drawings one form thereof which is at present preferred by me, since it will give in practice satisfactory and reliable results, althoughit is'to be understood (that the various instrumentalities of which my in- 80 vention consists can be variously arranged and organized and that my invention is not limited to the precise arrangement and organizationof these instrumentalities as herein shown vand described..

Figure 1 represents a side elevation of an automatic safety latch embodying my invention, the door and furnace front being shown in section, the full lines indicating the latched position, and the dotted lines the parts in unlatched position.

Fig. 2 represents a plan view of Fig.. 1. Fig.- 3 represents a' fragmentary side elevational detail of handle member removed. Fig. 4 represents a frontelevation of the handle carrying plate removed from the. door. Y f

Fig. 5 represents a side elevation 'ofV Similar numerals of reference indicate corresponding parts.

Referring to the drawings 1 designates a boiler front, and 2 a fire door hinged thereto so as to close the irebox opening 3 in any conventional manner, the location ofthe hinges not being shown,

. which terminates rearwardly in a shoulderA as the same per se form no part of the invention., s I

4e designates a bracket, conveniently secured to the boiler front above the door by bolts or other'fastening devices 5-6, and 6G formed With ears 7-S which form a fork through which passes the fulcrum pin J of a pivoted gravity latch 10, the lower rear end of which is formed with a bottom lug 11 adapted when the latch is in its 65 door-lookin position to engage a stoel?, 1n the brac et Ll, which prevents the from dropping below its latching position.

rlhe under front face of the latch is formed with a curved surface or cam 13, le

141, above which the under surface of the l latch is cut away to form a recess 16 designates a plate whose upper end serves as a terminal dog 29 to engage the "Io shoulder le, and is formed with ears 1.-18, which is bolted by bolts 19-20 or the n J to the re door 2, so that said plate ari?. door move as a unit. The ears 17-18 are preferably about mid-way of the length of the plate 164 `and formed with Yapertured bearings 21-,22 for a fulcrum pin 23 which constitutes the fulcrum of a swinging handie member or latch operating linger piece 24 which extends vertically and terminates 85 apertured at 27, which in the mounting of l the parts fits between the ears 17 and 18 of the plate 16, and through the introduction of .a fulcrum pin 23 through the aperture serves asa means for the mounting of the handle member upon the plate 16 of the door '2.

t will bev seen from theforegoing that nor ally, when the door is locked by the latch, the handlemember as a `whole occupies the inclined position represented in full lines in F ig.` 1. When, then, in order to open the door', the finger ieee 24 is grasped by the hand, and pulled` orwardly 1nto\the positionseen in dotted lines in Figil, thecontact and inward movement of its curved,A

end 25 with and against the cam surface 13 of the latch, will first raise the latch to free it from the upper dog 29 on the plate 16, and will then encounter a stop lug 28 on the front face ofthe plate 16, and in such practically vertical position will retain the latch.

its normal position, and the lug 11, being then in engagement with the stop 12, will retain said latch in its dropped or substantially horizontal position, and ready to be again lifted and permitted to drop to engage within its shouldered recess 14--15 the terminal `dog 29 and the top of the plate 16 when the door is again closed. l

It will be apparent from the foregoing that my novel device consists of a minimum number of parts, which can be cheaply produced, and which require very little machining and iitting and can be readily applied to existing furnace fronts and doors without necessitatln any change or dismantling thereof lan when my novel device is installed in position, it is automatic in its operation, a pull on the linger piece 241 Vfirst raising the latch 10 whereupon the door can be opened, and when the door is being closed the terminal dog 29 of the plate\ 16 rides under the cam 18 thereby lifting the ylatchlO, which automatically drops and interlocks with the dog when the door is closed. Y

While I have described my devide as particularly adapted to furnace fronts and doors, it will be understood that it is adapt ed for other analogous and kindred uses.

It will now be apparent that I have devised a novel and useful automatic safety latch for furnace doors which embodies the features of advantage enumerated as desirable in the statement of the invention and the above description, and while I have, in the present instance, shown and described a preferred embodiment thereof which will give in practice satisfactory and reliable results, it is to be understood that such embodiment is susceptible of modification in various particulars without departing from the spirit or scope of the invention or sacriicing any of its advantages.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is

In an automatic safety latch for furnace doors, a gravity latch pivotally sup/ported and havingy its outer portion provided with a bottom cam, a shoulder, and a recess and its inner end provided with a stop for holding said latch normally horizontal, a furnace door, a plate attached thereto and having an upper terminal dog adapted to interlock with the recess of said latch, a forwardly projecting stop on said plate below said dog, and a latch operating linger piece pivotally mounted on said plate, and having its lower grasping portion below its pivot, the upper end of said finger piece being defiected and adapted to engage the bottom of said latch cam, and raise said latch when said finger piece is initially rocked to open said door, said iinger piecenormally standing in an inclined position and the rearward vmovement .of its upper portion being limited fby its Contact with said stop.

EDWARD L. BURKY.

Witnesses:

E. C. SHUMATE, D. L. SLEsor. 

